This invention relates to a dual composition hard-coated chewing gum, i.e., a hard-coated chewing gum in which the hard coating is composed of two components, each having its own composition. More particularly, this invention relates to such a chewing gum having an improved coating quality and extended shelf life.
Specifically, this invention relates to a chewing gum in pellet form, having one or more sequentially added coats of xylitol and hydrogenated isomaltulose. The hard pellets are prepared by coating a gum core with syrups, which include xylitol and hydrogenated isomaltulose. The coated gum has improved coating quality and longer shelf life.
Chewing gums, including pellet chewing gums, are frequently enclosed with hard or soft coatings. Coatings provide an opportunity for the manufacturer to vary product characteristics such as taste, appearance and nutritional value. In recent years, efforts have been devoted to producing sugarless hard coatings for use in chewing gum. Sugarless coatings which have been investigated include coatings containing compounds such as xylitol, sorbitol, mannitol, and hydrogenated starch hydrolysates.
U.S. Pat. No. 4,792,453, issued Dec. 20, 1988, to Michael A. Reed et al., discloses a chewing gum having a sugarless chewing gum center coated with a syrup containing hydrogenated isomaltulose. The sugarless center may include various constituents such as water, an insoluble gum base, a bulking agent, a softener, an artificial sweetener, and a flavoring agent. The sugarless chewing gum center of the reference has a water content of less than about 2.5 weight percent, preferably less than about 1.5 weight percent and most preferably less than about 1.0 weight percent. The use of a center having a low water content, is intended to prevent or reduce the tendency of the gum center from being a water donor to the hard coating.
Sugarless gums coated with hydrogenated isomaltulose-containing syrup possess excellent appearance, taste, texture, mouth feel, and other desirable properties of hard coated chewing gums. Also, it has been found that the relatively anhydrous gum center has the capability of pulling moisture from the hydrogenated isomaltulose-containing coating, causing the coating to exhibit superior hardness. This moisture-pulling from the gum center is attributable, in large part, to the use of glycerin as a softener in the gum center. The moisture-pulling effect is the most pronounced in hard coated chewing gums which contain moderate or relatively high amounts of glycerin in the chewing gum center, on the order of from about 5 to about 15 percent by weight of the chewing gum center.
The tendency of glycerin to pull moisture from the hydrogenated isomaltulose-containing coating can operate as a disadvantage in certain pellet-shaped hard coated chewing gums which, due to their shape, are difficult to isolate from a moisture-containing environment by packaging. For example, pellet gum which is shaped like pillows is difficult to protect from moisture because it is difficult to form a good quality, low or non-moisture permeable package which is suitable for these pellets.
Hydrogenated isomaltulose is a monohydrate. If the hydrogenated isomaltulose-containing coating on the pellet gum becomes too dry, e.g. due to the presence of glycerin, the coating becomes more hygroscopic and begins to absorb moisture from the surrounding atmosphere. This continuous drying and absorption of moisture from the atmosphere, reduces the shelf life of the pellet gum by causing the coating to soften and lose its desirable texture, appearance and mouth feel. Thus, the coating itself must be sufficiently shelf stable against moisture absorption so as not to allow the coating to deteriorate during its shelf life.
Commonly assigned U.S. patent application Ser. No. 07/855,251, filed Mar. 23, 1992, by Michael A. Reed and Jeffrey S Hook, entitled HARD COATED GUM WITH IMPROVED SHELF LIFE, discloses a chewing gum in pellet form which includes a center portion and an outer coating which contains hydrogenated isomaltulose.
Coating with xylitol is described in U.S. Pat. Nos. 4,105,801, issued Aug. 8, 1978, to Dogliotti; 4,127,677, issued Nov. 28, 1978, to Fronczowski et al.; 4,146,653, issued Mar. 27, 1979, to Mader et al.; 4,681,766, issued Jul. 21, 1987, to Huzinec et al.; 4,786,511, issued Nov. 22, 1988, also to Huzinec et al.; and 4,828,845, issued May 9, 1989, to Zamudio-Tena et al.